Problem: Simplify the following expression: $x = \dfrac{7k - 9}{7k + 10} \div \dfrac{1}{7}$
Solution: Dividing by a number is the same as multiplying by its inverse. $x = \dfrac{7k - 9}{7k + 10} \times \dfrac{7}{1}$ When multiplying fractions, we multiply the numerators and the denominators. $x = \dfrac{(7k - 9) \times 7} {(7k + 10) \times 1}$ $x = \dfrac{49k - 63}{7k + 10}$